45999 ÷ 9 = 5111 R0
We're going to perform division on 45999 with 9 as the divisor.

Step 1:
9 goes into 4 0 times with a remainder of 4.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 4 to get 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 9

Step 2:
9 goes into 45 5 times with a remainder of 0.
Write down 5 as next digit of of the result. 
Result so far: 5
Subtract 45 from 45 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 9

Step 3:
9 goes into 9 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 51
Subtract 9 from 9 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 9

Step 4:
9 goes into 9 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 511
Subtract 9 from 9 to get 0.
Bring next digit (9) of the dividend behind the 0 and repeat the process: 9 / 9

Step 5:
9 goes into 9 1 times with a remainder of 0.
Write down 1 as next digit of of the result. 
Result so far: 5111
Subtract 9 from 9 to get 0.

The final result is 5111 with a remainder of 0.